Was Abraham really a man of faith? Did he really believe he would have a son as promised?

–He brought with him his possessions and nephew Lot (“heir apparent”) when God told him to leave everything, and everyone, behind. Cf. Gen. 12:1 and 12:5.

–He moved southwards even after settling in Canaan, the promised land, thinking since the Canaanites were still there he should therefore go elsewhere.

–He was so afraid to be killed by Pharaoh, and that’s before he had a son.

–He thought Sarai being taken by Pharaoh as wife was okay, thinking his own son(s), if he would have any, would be from another (perhaps younger) woman anyway.

–He actually agreed to have a son with his concubine Hagap, thinking Sarai was probably right that she’s too old to conceive. Also Gen. 18:12-15.

How then was Abraham a man of faith? Why is he the father of faith, and we his children?

1. If we are to say Abraham was a man of faith, it was because he was willing to sacrifice Isaac, not because he believed in the birth of Isaac before it took place.

–Believing in the gift of a son has not much significance, at least not to so many of the chosen people. God surely does not promise the birth of a son to a whole lot of people. And the fact that Abraham believed in the gift of a son, even if he did, has no theological bearing on us.

–It does not explain why we, by faith, are children of Abraham.

2. But Abraham was a man of faith because when he was willing to sacrifice his son, his action truly demonstrated that he believed he would not lose his son in the sacrifice (Gen. 22:1-19). He was confident that both he and his son would go back to the servants after the sacrifice (22:5). And he explicitly said to Isaac that God would prepare the lamb needed for the sacrifice (22:8).

–This explains why Abraham is called the father of faith and we are his children: because, following him, we all believe in the same thing: that God would prepare, or has already prepared, a lamb to take our place in death.

–Also because: we, like his child Isaac, are saved from death by a lamb of God.

–This implies the beautiful idea that ultimately the Old and New Testaments are more similar than different – God made the old covenant with Abraham, because Abraham believed that God would prepare a lamb to take the place of the children of Abraham (signified by Isaac, and signifying all believers in the New Testament).